Heavy duty lift

ABSTRACT

A lift device for use with farm tractors and similar mechanisms is described. Preferably the lift is used with and attached to the rear of farm tractors equipped both with conventional lifting arms and a conventional remote controlled double-acting hydraulic cylinder. The lift is capable of raising heavy loads to high elevations, is light weight, and can be installed and used by one operator. In addition the lift can readily be fabricated from low cost, readily available component parts.

I United States Patent m1 3,593,858

[72] Inventor Shelton Rulfin Rm. oak Grove La "263 2,382,767 8/1945Zellman l. 2l2/144 H pp No 707 825 2733318 2/1956 Gregersen 212/8 FiledFeb. 23 I968 2,878.946 3/1959 wlrkkalal. .4 212/59 [45] Patented July20, 1971 Primary Examiner-Andres H. Nielsen Attorney-John Fl Sieberth{54] HEAVY DUTY LlFI' 9 Claims, 3 Drawing Figs. I Cl 212/8, ABSTRACT: Alift device for use with farm tractors and 212,59112/144 similarmechanisms is described Preferably the lift is used [5]] hit. Cl B664:23/00 i and attached to the realof farm tractors equipped both of Search212/8, with conventional lifting arms and a conventional remote con- 17,144 trolled double-acting hydraulic cylinder. The lift is capable ofraising heavy loads to high elevations, is light weight, and can (56]Reerences Cited be installed and used by one operator. In addition thelift can UNITED STATES PATENTS 322,756 7/1885 Sharp readily befabricated from low cost, readily available component parts.

PATENTEU JUL20 um ATTORNEY HEAVY DUTY LIFT This invention relates to alift or hoist device adapted for use with farm tractors and similarequipment. More particularly, this invention relates to a heavy dutyutility high lift which can readily and advantageously be employed withtractors or other vehicles equipped with a three point hitch wherein theupper connecting link involves a remote control hydraulic cylinder ofthe type which is standard equipment on modern farm tractors.

The objects, advantages, features, characteristics, and embodiments ofthis invention will become readily apparent from the ensuingdescription, appended claims and accompanying Figures of the Drawing inwhich:

FIG. I depicts in perspective a preferred overall lift construction inaccordance with this invention;

FIG. 2 illustrates an optional jib construction which may be used inconjunction with the lift devices provided by this invention; and

FIG. 3 schematically represents in side view some of the geometricalaspects of the lift construction of this invention.

In accordance with its basic teachings, this invention pro vides a liftwhich comprises:

a. an elongate deflected pole defining an obtuse angle and having alonger segment and a shorter segment;

b. a gantry bar affixed to said shorter segment and extending above anirn nary line projected rearwardly from said longer segment;

c. means for pivotally attaching and supporting the pole in proximity tothe rearward terminus of said shorter segment to permit arcuate motionof the pole in a vertical plane; and

d. means for pivotally connecting the upper end of the gantry bar to areciprocative driving member having a relatively short linear strokesuch that short rearward motion of the driving member will causeexaggerated vertical arcuate motion of the forward end of said longersegment. While the means of (c) above may be of various types andconstructions, it is generally preferable to provide a lateral two pointhitch assembly to which is attached the rearward terminus of the shortersegment of the deflected pole.

The means of (d) above likewise may be of various types andconstructions although generally speaking a form of linkage involving ahydraulic cylinder is most convenient. Thus when this preferred linkageis utilized in combination with the preferred lateral two point hitchassembly noted above, the overall lift is connected to the tractor orother suitable vehicle by means of a three point hitch. For example,when the lift constructions of this invention are to be linked to a farmtractor by means of the preferred modes of attachment, the means of (c)above comprise a transverse support member carrying a pair of pivotalhitch assemblies adapted to operatively engage the lifting arms of thetractor and the means of (d) above involve linkage to a double-actingcylinder associated with the tractor. As is well known, modern farmtractors are almost universally equipped with such lifting arms andremotely controlled double-acting hydraulic cylinders.

Although the extent of the deflection in the foregoing pole may bevaried to accommodate the size and nature of the device with which thelift construction is utilized, the obtuse angle in the pole ispreferably in the range of about 115to about 155". This permits the liftto be readily utilized with modern farm tractors.

As noted above the gantry bar is affixed to the shorter segment of thedeflected pole and extends above an imaginary line projected rearwardlyfrom the longer segment of the pole. It will be appreciated of coursethat the length, positioning and angular deflection of the gantry barrelative to the shorter segment of the pole may be varied depending uponthe vehicle or power source with which the lift is to be associated.When providing a lift construction of this invention for use with modernfarm tractors, especially those equipped with doubleacting hydrauliccylinders having an 8 to 10 inch stroke, it is desirable that the gantrybar be substantially perpendicular to the imaginary line projectedrearwardly from the longer segment of the deflected pole. In addition,the gantry bar will most often be affixed to the shorter segment of thepole at a locus intermediate the ends of that shorter segment.

Referring now to FIG. l, a particularly preferred lift of this inventioninvolves an elongate deflected pole indicated generally by the numeral110, this pole having a longer segment 12 and a shorter segment 14.Gantry bar to extends upwardly from segment 14 and carries near its top,lug 118 permitting pivotal attachment to a hydraulic cylinder (notshown). The lateral two point hitch assembly discussed above ispositioned in proximity to the terminus of shorter segment 14 of pole10. This assembly comprises transverse bar carrying two spaced-apartpairs of laterally positioned plates 21, 22 and 23, 24 fitted withapertures to receive pivot bolts (not shown). This enables pivotalconnection of the lift to the conventional lifting arms (not shown) ofmodern farm tractors and like vehicles. Thus the lift is pivotallysupported by means of a three point hitch assembly involving lug 18,plates 21, 22 and plates 23, 24.

Elongate reinforcing member or rod 25 extends between approximately theupper end of gantry bar 16 and approximately the upper forward endoflonger segment 12 of pole 10. For added strength, gusset 26, bracerods 27, 28 and plate support 29 are provided. Thus rod 25 works inconcert with pole 10 preferably via various points of attachment.

An elongate bracing member, viz., braces 30 and 32, respectively,extends between approximately each respective outer end of transversebar 20 and a locus intermediate the ends of the longer segment 12 ofpole llll).

Preferably, the forward end oflonger segment 12 of pole 10 is providedwith means for detachably attaching a load at various distances from theopposite end of the pole. Thus in the form depicted in FIG. 1, plate 34is affixed to the underside of the forward end of longer segment 12 andis provided with a plurality of apertures for hooking, tying orotherwise attaching a load to the lift.

When employed with the power auxiliaries available on conventional farmtractors, the lift may be raised or loweredby force supplied by thelifting arms alone, by the hydraulic cylinder alone, or by thecombination of these. The power source utilized will to some extent bedependent upon the elevation to or from which the lift is to beoperated. For example, the lift can be raised to or lowered from anintermediate elevation simply by raising or lowering (as the case maybe) the lifting arms of the tractor. In other words, the hydrauliccylinder need not be actuated to effect such intermediate raising orlowering; the cylinder assembly may simply be used as the upper pivotalconnection of the three point hitch. Alternatively, intermediateelevations may be achieved by suitably activating the hydraulic systemwithout actuating the lifting arms. However, where the lift is to beraised to its highest elevation or lowered to its lowest elevation, thelifting arms and the hydraulic cylinder assembly will] both be actuated.

Experience has shown that the lift constructions of this inventionpossess a number of advantageous features. For example, a lift such asdepicted in FIG. ll can be fabricated at relatively low cost fromreadily available low-cost component parts. Spot welding or relatedtechniques are conveniently used in such fabrication operations.Moreover, the lift of this invention is very easy to install on atractor or related device. It has been found that one man can effectthis installation in a matter ofa few minutes.

Furthermore, the lift construction of this invention is very sturdy anddurable. In fact, a unit of this invention attached to a large sizedfarm tractor was found capable of lifting a heavier load than a moreexpensive tractor which was designed for the sole function of heavy dutyloading and unloading operations. Thus the lift construction of thisinvention renders common farm tractors and like vehicles capable of notonly performing their usual functions but. the function of raising andlowering heavy loads as effectively if not more effectively, thanexpensive lift devices which have no other utilities.

Still another advantage of the lift construction of this invention isthe fact that loads can be raised to relatively high levels. Forexample, a commercial farm tractor was equipped with a lift having ahorizontal length of essentially 12 feet and proportioned generally inaccordance with FIG. 1. By combined use of the lifting arms and thedouble-acting hydraulic cylinder (8 inch stroke) the forward end of thepole was readily raised to an elevation approximately 13 feet aboveground level and could of course be raised and lowered to anyintermediate height.

Still other advantages of this invention include the facts that the liftconstruction is light in weight and that it can be used for a widevariety of farm and commercial lifting and transporting operations. Byway of example, the lift may take the place of winch trucks or front-endloaders which are generally too expensive for most farm and utilityuses. Because the lift can be installed quickly by one operator, laborcosts are kept to a minimum. For example, a single operator can utilizethe present device for loading heavy objects on high surfaces such astruck beds, freight cars, and the like.

One of the features of this invention is the fact that the gantry barextends above an imaginary line projected rearwardly from the longersegment of the deflected pole. In the first place, the force exertedupon the overall lift by the pushrod or ram of the hydraulic cylinder isapplied at the upper end of the gantry bar. Therefore because this upperend is elevated in this manner the amount of leverage applied to theoverall system is considerable and contributes materially to the abilityof the lift to raise and carry heavy loads. In the second place theextension of the gantry bar above this imaginary line enables the upperportion of the gantry bar to serve as a connection for rod 25 whichgreatly reinforces the load carrying ability of pole 10.

FIG. 2 depicts an auxiliary jib construction which may be used inconjunction with the lift when it is desired to transport wide loads. Itwill be seen that this jib involves arm 36 which may be afi'rxed atvarious locations to plate 34 by means of an aperture therein and pivotbolt 38. The opposite end of arm 36 is provided with aperture 39 forattachment to the load. Knee brace 40 is affixed to plate 34 by means ofbolt 41 and to arm 36 by means of bolt 42. In this way, arm 36 isdeflected outwardly from pole 10 and held in this position so that aspole 10 is raised, the load remains suspended generally below but out ofcontact with longer segment 12 and the remainder of the associated partsof the overall lift.

FIG. 3 further represents schematically some of the features of thepresent lift construction. More particularly, it will be seen from FIG.3 that gantry bar 16 extends above imaginary line C projected rearwardlyfrom longer segment 12. As noted above, the angle of deflection(depicted as alpha in FIG. 3) is preferably in the range of from about 115 to about 155 and for best results gantry bar 16 is substantiallyperpendicular to imaginary line C as shown in FIG. 3. This means thatangle beta represents the difference between 180 and the degreesrepresented by angle alpha. For use with most common farm tractors anglealpha is most preferably in the order of about 135 with angle beta beingin the order of about 45.

By virtue of the foregoing features illustrated by FIG. 3, a relativelyshort rearward movement of the top of gantry bar 16 (i.e., motion asdepicted by arrow 0 on FIG. 3) results in exaggerated vertical arcuatemotion of the forward end of segment 12 (as depicted by arrow b of FIG.3).

FIG. 3 also illustrates the fact that various loads may besimultaneously carried by pole 10 such as by attachment at two or moreloci schematically depicted as L L,, L and L Moreover, a single load maybe carried at various distances from the opposite end of the pole, forexample, it may be attached to the forward end (locus L,) or it may beattached at a point closer to the rearward terminus of the pole, such asat L L or L This feature is advantageous in that the lifting forcebecomes greater as the load is affixed closer to the rearward terminusof the pole. Thus it is possible to raise a heavier load at L than at L,although of course the load at L can be raised to a higher elevation.

The particular dimensions and materials of construction of the devicesof this invention may of course be varied to suit the needs of theoccasion. Particularly good results have been achieved by constructing alift in accordance with FIG. 1 wherein pole 10 was made 2%" standardwall pipe, longer segment 12 being essentially 9'6 in length and shortersegment 14 being essentially 2'4" in length. Angle alpha wasapproximately Gantry bar 16 was made from an iron bar (3" k in thicknessand essentially 15%" in length). It was affixed to essentially themidpoint of the shorter segment 14 and arranged perpendicularly to theimaginary line projected rear wardly from longer segment 12 such thatangle beta was essen tially 45. Rod 25 was made from three-quarter inchiron rod and braces 30 and 32 from 1%" standard wall iron pipe. Plate 34was made from 3"X%" iron plate, 5 inch in length, which contained aplurality of 1 inch apertures on 11 inch centers. The unit involvedwelded construction and was found to give trouble-free service whenapplied to various lifting and carrying operations with a commercialfarm tractor equipped with a remotely-controlled double-acting hydrauliccylinder having an 8 inch stroke. The strength of this particularconstruction can be appreciated from the fact that it could be used tolift a 2-ton load attached to the forwardmost aperture in plate 34.Indeed this construction was capable of lifting even greater loads whenaffixed to the more rearwardly-positioned apertures in plate 34.

Because of the great lifting strength of the present lift construction,it is of course desirable to ensure, when seeking to raise exceptionallyheavy loads, that the forward end of the tractor or other vehicle withwhich it is associated is sufficiently heavy to prevent overturning thetractor or vehicle. In those instances where the weight of the loadwould tend to overturn the tractor or similar vehicle, the same mayeither be temporarily weighted down at its front end or suitably bracedto the ground or floor surface so as to prevent the possibility ofoverturning.

Inasmuch as the principles, features, advantages, and characteristics ofthis invention are susceptible to considerable variation withoutdeparting from the true spirit and scope of this invention, theforegoing specific exempliflcations of a particularly preferredembodiment of the foregoing invention should not be construed as beinglimitative. By way of example, the particularly preferred lift justdescribed involved longer segment 12 being essentially four times thelength of shorter segment 14. It will be appreciated and understood thatthis ratio may be varied, depending for example upon the particular usesto which the lift is to be put, the magnitude of the loads to becarried, the size and shape of the vehicle or other power source withwhich the lift is to be associated, and the like. Generally speakinghowever, the length ratio (longer segmentzshorter segment) will rangefrom about 8:1 to about 2:1; ratios in the range from about 6:1 to about3:1 being preferred for most applications.

It is of course evident that the manner by which the hydraulic cylinderis linked between the body of the tractor or other vehicle and gantrybar 16 is susceptible to considerable variation. For example the outerend of the pushrod of the hydraulic cylinder may be connected to a lugor similar attachment means on the tractor and the opposite end of thecylinder pivotally connected via lug 18 to the gantry bar. The converseform of connection is also suitable, in which case the outer end of thepushrod is pivotally connected to lug l8 and the opposite end of thecylinder linked to the body of the tractor. Similarly, it is entirelypractical to employ suitable supplemental connecting links (1) betweenthe body of the tractor and either end of the hydraulic cylindermechanism, (2) between lug 18 and either end of the hydraulic cylindermechanism, or (3) between both (1) and (2). It has been foundefficacious, for example, to insert between the attachment lug on therearward end of one commercially marketed tractor and the hydrauliccylinder mechanism, an iron bar approximately 10 inches in length and 2"in thickness having 1 inch diameter holes on 8 inch centers. Suchsupplemental connecting links do not alter the functioning of theoverall system, but do which may be utilized in the practice of thisinvention will now be evident to those skilled in the art and areembodied in the following claims.

lclaim:

l. A portablelift for farm tractors or the like which comprises:

a. an elongate deflected pole defining an obtuse angle and having alonger segment and a shorter segment;

b. a gantry bar affixed to said shorter segment and extending above animaginary line projected rearwardly from said longer segment;

c. means for pivotally attaching and supporting the pole in proximity tothe rearward terminus of said shorter segment to permit arcuate motionof the pole in a vertical plane; and

d. means for pivotally connecting the upper end of the gantry bar to areciprocative driving member having a relatively short linear strokesuch that short rearward motion of the driving member will causeexaggerated vertical arcuate motion of the forward end of said longersegment;

the forward end of the longer segment of said pole being provided withmeans for detachably attaching a load at various distances from theopposite end of the pole.

2. The device of claim 1 further characterized in that the means of (c)comprise a lateral two'point hitch assembly.

3. The device of claim 1 further characterized in that said obtuse angleis in the range of from about 115 to about 155 and in that said gantrybar is substantially perpendicular to the imaginary line projectedrearwardly from the longer segment of said pole.

4. The device of claim 1 further characterized in that an elongatereinforcing member extends between approximately the upper end of saidgantry bar and approximately the upper forward end of the longer segmentof said pole.

5. The device of claim 1 further characterized in that the means of (c)comprise a transverse support member carrying a pair of pivotal hitchassemblies adapted to operatively engage the lifting arms of a tractorand in that an elongate bracing member extends between approximatelyeach respective outer end of said transverse support member and a locusinter mediate the ends of the longer segment of said pole.

6. The device of claim 1 further characterized in that the means of (c)comprise a transverse support member carrying a pair of pivotal hitchassemblies adapted to operatively engage the lifting arms of a tractorand in that said gantry bar is affixed to said pole intermediate theends of the shorter segment thereof and is positioned and adapted to beactuated by a hydraulic cylinder associated with the tractor.

7. The device of claim 1 further characterized in that said obtuse angleis in the range of from about 1 to about 155;

in that said gantry bar is substantially perpendicular to the imaginaryline projected rearwardly from the longer segment of said pole;

in that an elongate reinforcing member extends between approximately theupper end of said gantry bar and approximately the upper forward end ofthe longer segment of said pole;

in that the means of (c) comprise a transverse support member carrying apair of pivotal hitch assemblies adapted to operatively engage thelifting arms of a trac- 01;

in that an elongate bracing member extends between approximately eachrespective outer end of said transverse support member and a locusintermediate the ends of the longer segment of said pole;

in that said gantry bar is affixed to said pole intermediate the ends ofthe shorter segment thereof and is positioned and adapted to be actuatedby a double acting hydraulic cylinder associated with the tractor; andin that the lower forward end of the longer segment of said pole 15provided with said means for detachably attaching a load at variousdistances from the opposite end of the pole.

8. The device of claim 1 further characterized in that said obtuse angleis in the range of from about 1 15 to about 155; in that said gantry baris substantially perpendicular to the imaginary line projectedrearwardly from the longer segment of said pole; and in that the lengthratio, said longer segment: said shorter segment, is in the range offrom about 8:1 to abou 2:1.

9. A portable lift for farm tractors or the like which comprises:

a. an elongate deflected pole defining an obtuse angle in the range offrom about to about 115 and having a longer segment and a shortersegment;

b. a gantry bar affixed to said shorter segment and extending above andbeing substantially perpendicular to an imaginary line projectedrearwardly from said longer segment;

c. means for pivotally attaching and supporting the pole in proximity tothe rearward terminus of shorter segment to permit arcuate motion of thepole in a vertical plane, said means comprising a transverse supportmember carrying a pair of pivotal hitch assemblies adapted tooperatively engage the lifting arms of a tractor;

d. means for pivotally connecting the upper end of the gantry bar to areciprocative driving member having a relatively short linear strokesuch that short rearward motion of the driving member will causeexaggerated vertical arcuate motion of the forward end of said longersegment;

e. an elongate reinforcing member extending between approximately theupper end of said gantry bar and approximately the upper forward end ofthe longer segment of said pole; and

f. an elongate bracing member extending between approximately eachrespective outer end of said transverse support member and a locusintermediate the ends of the longer segment of said pole.

Patent No. 3, 595, 5 Dated ly 97 Invent r( Shelton Ruffin It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 5, lines 54-56, delete the sentence reading "This means thatangle beta represents the difference between 180 and the degreesrepresented by angle alpha."

Column I, line 5 reads made 2-1/2" should read made of 2-1/2" Column 4,lines 8 and 9 reads (5" X l 2 in thickness should read (3" x l 2" inthickness Column I, line 15 reads 5 inch in length should read 5 feet inlength Column 6, line 52 reads 115 to about 115 should read 115 to about155 Signed and sealed this 7th day of March 1972.

(SEAL) Attest:

EIBWARD M.FLI:ITCHER,JR. ROBERT GOTTSCHALK Ab'GSStlng OfficerCommissioner of Patents

1. A portable lift for farm tractors or the like which comprises: a. anelongate deflected pole defining an obtuse angle and having a longersegment and a shorter segment; b. a gantry bar affixed to said shortersegment and extending above an imaginary line projected rearwardly fromsaid longer segment; c. means for pivotally attaching and supporting thepole in proximity to the rearward terminus of said shorter segment topermit arcuate motion of the pole in a vertical plane; and d. means forpivotally connecting the upper end of the gantry bar to a reciprocativedriving member having a relatively short linear stroke such that shortrearward motion of the driving member will cause exaggerated verticalarcuate motion of the forward end of said longer segment; the forwardend of the longer segment of said pole being provided with means fordetachably attaching a load at various distances from the opposite endof the pole.
 2. The device of claim 1 further characterized in that themeans of (c) comprise a lateral two-point hitch assembly.
 3. The deviceof claim 1 further characterized in that said obtusE angle is in therange of from about 115* to about 155* and in that said gantry bar issubstantially perpendicular to the imaginary line projected rearwardlyfrom the longer segment of said pole.
 4. The device of claim 1 furthercharacterized in that an elongate reinforcing member extends betweenapproximately the upper end of said gantry bar and approximately theupper forward end of the longer segment of said pole.
 5. The device ofclaim 1 further characterized in that the means of (c) comprise atransverse support member carrying a pair of pivotal hitch assembliesadapted to operatively engage the lifting arms of a tractor and in thatan elongate bracing member extends between approximately each respectiveouter end of said transverse support member and a locus intermediate theends of the longer segment of said pole.
 6. The device of claim 1further characterized in that the means of (c) comprise a transversesupport member carrying a pair of pivotal hitch assemblies adapted tooperatively engage the lifting arms of a tractor and in that said gantrybar is affixed to said pole intermediate the ends of the shorter segmentthereof and is positioned and adapted to be actuated by a hydrauliccylinder associated with the tractor.
 7. The device of claim 1 furthercharacterized in that said obtuse angle is in the range of from about115* to about 155*; in that said gantry bar is substantiallyperpendicular to the imaginary line projected rearwardly from the longersegment of said pole; in that an elongate reinforcing member extendsbetween approximately the upper end of said gantry bar and approximatelythe upper forward end of the longer segment of said pole; in that themeans of (c) comprise a transverse support member carrying a pair ofpivotal hitch assemblies adapted to operatively engage the lifting armsof a tractor; in that an elongate bracing member extends betweenapproximately each respective outer end of said transverse supportmember and a locus intermediate the ends of the longer segment of saidpole; in that said gantry bar is affixed to said pole intermediate theends of the shorter segment thereof and is positioned and adapted to beactuated by a double acting hydraulic cylinder associated with thetractor; and in that the lower forward end of the longer segment of saidpole is provided with said means for detachably attaching a load atvarious distances from the opposite end of the pole.
 8. The device ofclaim 1 further characterized in that said obtuse angle is in the rangeof from about 115* to about 155*; in that said gantry bar issubstantially perpendicular to the imaginary line projected rearwardlyfrom the longer segment of said pole; and in that the length ratio, saidlonger segment: said shorter segment, is in the range of from about 8:1to about 2:1.
 9. A portable lift for farm tractors or the like whichcomprises: a. an elongate deflected pole defining an obtuse angle in therange of from about 115* to about 115* and having a longer segment and ashorter segment; b. a gantry bar affixed to said shorter segment andextending above and being substantially perpendicular to an imaginaryline projected rearwardly from said longer segment; c. means forpivotally attaching and supporting the pole in proximity to the rearwardterminus of shorter segment to permit arcuate motion of the pole in avertical plane, said means comprising a transverse support membercarrying a pair of pivotal hitch assemblies adapted to operativelyengage the lifting arms of a tractor; d. means for pivotally connectingthe upper end of the gantry bar to a reciprocative driving member havinga relatively short linear stroke such that short rearward motion of thedriving member will cause exaggerated vertical arcuate motion of theforward end of said longer segment; e. an elongate reinforcing memberextending between approximately the upper end of said gantry bar andapproximately the upper forward end of the longer segment of said pole;and f. an elongate bracing member extending between approximately eachrespective outer end of said transverse support member and a locusintermediate the ends of the longer segment of said pole.